CUSTOMER'S PACKAGING MATERIAL TO RETURN

I have one scenario to solve.

A customer provides us with packaging material to be used as we send him the requested goods. The material he provides us has no value but quantity.

We use MIGO to the GR of the packaging related with the customer number and with movement type 561 V (GR per initial entry of stock to unrestricted stock of returnable packaging at a customer's stock) .

What I’m trying to do is to add the “customer’s packaging material” directly as one of the positions in the outbound delivery generated with reference to a sales order (editing with VL02n).

The movement type is determined directly from the schedule line category – my idea is to use the 562 V to reduce the 561 V stock… but I just get errors related to checks against the table 156S

Error while determining ref.mov.type for WM via Table 156S: 562/ /X/ /L/X/

And although I edited the table (SM31 - V_156SC_VC, following note 1733520) to add the alleged entries, I still getting the same error.

Question:

What’s your opinion about the solution to the scenario?

How could I overcome this error?

Thank you very much in advance, community!